Known, prior art dental burrs include, for example, those shown in U.S. Pat. Nos. 482,558; 2,358,432; 1,813,741; 2,338,437; 2,606,366; 2,901,826; 3,624,095; and 3,894,339; and French Pat. No. 931,489. A further cutting instrument is shown by U.S. Pat. No. 3,510,990.